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Re:Trial of a blood test that detects eight common forms of ... by tischler on Friday January 19, 2018 @04:13AM (#16184995)
As a reminder:

true positive rate (TPR, a.k.a. hit rate, recall, specificity)

TPR = TP / P = TP / (TP + FN)

specificity (SPC) or true negative rate

SPC = TN / N = TN / (TN + FP)

Re:Trial of a blood test that detects eight common forms of ... by kmmlng on Friday January 19, 2018 @04:36AM (#16185084)
You labelled both TPR and TNR as "specificity". True positive rate should be sensitivity.
Re:Trial of a blood test that detects eight common forms of ... by tischler on Friday January 19, 2018 @08:06AM (#16185905)
Oops, thanks. I've always had struggle remembering these terms because they are so confusing. "Specific" means that something only relates to one particular element X in a set of more than one thing. Given that meaning, one would expect specificity to mean "how good is the test at correctly reporting the thing it is designed to report X rather than confusing a different thing (an element from the complement of X) for X", but that is sensitivity. Instead, specificity means that with respect to the complement: "how good is the test at correctly reporting all the other elements in the set ¬X as negative rather than confusing an element from ¬X for X".

"Sensitive" has a clearer intuition: For example when you want to detect a weak signal, then if your antenna is more sensitive, you can better pick up the signal, thus you are better at telling whether the signal is really there (you have a better true positive rate).

I cannot think of a better name for TNR, though, other than simply sticking with TNR and TPR.

Re:Trial of a blood test that detects eight common forms of ... by kmmlng on Friday January 19, 2018 @08:54AM (#16186171)
Your sensitivity intuition is a fantastic way to remember it. I had to look it up myself, but hopefully this will finally make it stick :)